1. Field of the Invention
The present invention concerns a light source for illuminating all the optical fibers in a bundle of optical fibers. A device of this kind is placed at the entry end of the bundle and the light received by each optical fiber is transmitted to its exit end. The bundle of optical fibers may be used for display purposes, for example.
For the light to enter each of the optical fibers it must be at a small angle of incidence to the axis of the fiber; also, it is necessary for all the fibers to be lit uniformly so that they transmit substantially the same quantity of light.
2. Description of the Prior Art
When it is necessary to illuminate a bundle of optical fibers comprising a large number of fibers it is necessary, if good results are to be obtained, to divide the bundle into multiple groups of fibers which are assembled together in a sleeve to constitute a harness, as described in the document U.S. Pat. No. 3.683.167, each sleeve being illuminated by an electric lamp. To illuminate a bundle of 400 optical fibers, for example, the fibers are divided into two sets of 200 fibers which are assembled into a half-harness, each of the sets being illuminated by a separate electric lamp as described in the document GB-2.041.187.
This device is somewhat complex as it requires the bundles to be divided into several parts each comprising a sleeve and an associated lamp. Also, the reliability of this device is very poor since should a lamp fail the corresponding half-bundle is no longer illuminated; finally, the electrical power consumption is relatively high as two relatively high power (50 W) lamps are used.
Furthermore, the lack of homogeneity in the lamp affects the beam that it emits with the result that the light applied to the set of optical fibers is not homogeneously distributed.
An object of the present invention is a device for illuminating a bundle of optical fibers which enables the fibers to be illuminated homogeneously, which has improved reliability and which is of reduced cost.